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Luke

TfgCollectionView : Fetching thumbnail images from web

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Posted (edited)

Hi All,
i'm testing tfgCollectionView with this rest resource : http://jsonplaceholder.typicode.com/photos

In this test my CollectionView Style has 1 fgImage and 1 fgLabel.
I get the RestResouce with a TRESTRequest.ExecuteAsync and it works perfectly.
When i've the ExecuteAsync CallBack i parse the JSON output string and i fill my Photos collection (TList).
I do this step with a separate Task because i've 5000 items ( more or less).

When i link data to the CollectionView i call fgCollectionViewGetItemCount and fgCollectionView1BindItem.
If i bind only the fgLabel all works perfectly.
My problem is link the tfgImage to the thumbnail.
I post my code:

procedure TFramePhoto.fgCollectionView1BindItem(Sender: TObject;const AIndex: Integer; const AStyle: string; const AItem: TfgItemWrapper);
VAR Item:TPhotoData;
begin
  TRY
    Item:=RestPhotos.Items[AIndex];

    AItem.GetControlByLookupName<TfgLabel>('LblTitle').Text := Item.Ftitle;
    TfgAssetsManager.Current.AddBitmapFromUrlAsync(Item.FalbumId, Item.FthumbnailUrl,
    procedure (const AResultCode: Integer; const AResultMessage: string) begin
      AItem.GetControlByLookupName<TfgImage>('ImgAlbum').ImageName := Item.FalbumId;
    end);

  EXCEPT ON E:EXCEPTION DO
    FGX.Log.TfgLog.Log(TfgLogLevel.Debug,'fgCollectionView1BindItem ' + e.Message);
  END;
end;
 

Actually i'm saving the images in assets but i think it is a bad idea...
Can you suggest a best practice for this scenario ?

Thanks a lot guys,
Best Regards.

 

 

Edited by Luke

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Posted (edited)
if not TfgAssetsManager.Current.Contains(Item.FalbumId) then
   TfgAssetsManager.Current.AddBitmapFromUrlAsync(Item.FalbumId, Item.FthumbnailUrl);
AItem.GetControlByLookupName<TfgImage>('ImgAlbum').ImageName := Item.FalbumId;

Try it!

I think Item.FalbumId not uniq field for records, it needs to be replaced by Item.Id.

Edited by knsg12
  • Like 2

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Hi Knsg12,
you are right...
AlbumId is not unique... excuse me.
I check better if now it is solved.

Thanks a lot,
Luke.

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Hi All,
now my demo works better, thanks Knsg12.
However i've seen that TfgAssetsManager.Current.AddBitmapFromUrlAsync take a lot of time ( 20 - 30 seconds ) to download the thumbnail from  'https://via.placeholder.com/150/92c952'.

I've tried also to update your demo AsyncBitmapAssetDemo and i've replaced your sample url with mine.
The first execution take 20 second, the nexts less than 1 second.
How could be possibile ?
Many thanks guys for your support.
 

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When you query a picture for the first time, it uploads it and save to Assets, the next time it will no longer upload a picture. And your fgimage always geting pic from Assets.

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Hi Knsg12, thanks for support.
I will do more tests and i will close the post if solved.
Thanks a lot.
 

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